Bug 1189847 - [mozversion] mozversion requires mozdevice, it shoudn't. r=dhunt

This make the mozdevice dependency of mozversion optional.

testing/mozbase/docs/mozversion.rst

@@ -6,6 +6,15 @@ provides version information such as the application name and the changesets
 that it has been built from. This is commonly used in reporting or for
 conditional logic based on the application under test.
 
+Note that mozversion can report the version of remote devices (e.g. Firefox OS)
+but it requires the :mod:`mozdevice` dependency in that case. You can require it
+along with mozversion by using the extra *device* dependency:
+
+.. code-block:: bash
+
+  pip install mozversion[device]
+
+
 API Usage
 ---------
 

testing/mozbase/mozversion/mozversion/mozversion.py

@@ -12,7 +12,6 @@ import tempfile
 import xml.dom.minidom
 import zipfile
 
-import mozdevice
 import mozfile
 import mozlog
 
@@ -189,6 +188,13 @@ class RemoteB2GVersion(B2GVersion):
                  **kwargs):
         B2GVersion.__init__(self, sources, **kwargs)
 
+        try:
+            import mozdevice
+        except ImportError:
+            self._logger.critical("mozdevice is required to get the version"
+                                  " of a remote device")
+            raise
+
         if dm_type == 'adb':
             dm = mozdevice.DeviceManagerADB(deviceSerial=device_serial,
                                             serverHost=adb_host,

testing/mozbase/mozversion/setup.py

@@ -6,9 +6,6 @@ from setuptools import setup
 
 PACKAGE_VERSION = '1.3'
 
-dependencies = ['mozdevice >= 0.44',
-                'mozfile >= 1.0',
-                'mozlog >= 3.0']
 
 setup(name='mozversion',
       version=PACKAGE_VERSION,
@@ -23,7 +20,8 @@ setup(name='mozversion',
       packages=['mozversion'],
       include_package_data=True,
       zip_safe=False,
-      install_requires=dependencies,
+      install_requires=['mozfile >= 1.0', 'mozlog >= 3.0'],
+      extras_require={'device': ['mozdevice >= 0.44']},
       entry_points="""
       # -*- Entry points: -*-
       [console_scripts]